1. Field of the Invention
The present invention relates to devices, systems, and methods for delivering an intraocular lens into an eye. More particularly, the invention relates to devices, systems, and methods in which the intraocular lens is loaded from the front end of the device.
2. Description of the Related Art
Intraocular lenses (IOLs) may be implanted in the eye of a subject to replace the natural crystalline lens or to otherwise modify the vision of an eye containing either the natural lens or another IOL. IOLs commonly include an optic and one or more flexible fixation members or haptics extending from the optic to secure and center the optic within the eye. When the IOL replaces the natural lens, the natural lens must first be removed, for instance, using a phacoemulsification system. The IOL is then generally implanted using an insertion apparatus or device that rolls, folds, or otherwise configures the lens for delivery through a small incision in the eye in a way that reduces trauma and expedites post-surgery healing.
Inserters for delivering IOLs into the eye generally employ a cartridge having a hollow insertion tube or cannula through which the folded IOL is passed using a pushrod. The inserter may be designed for reuse, in which case the inserter components are usually made of some type of metal alloy. Alternatively, disposable inserters may be used that are made of less expensive materials, such as plastics, and that remain in a sterile package until ready for use. The pushrod and insertion tube may be designed to advantageously provide the surgeon precise control of the IOL as it is placed inside the eye, for example as disclosed in U.S. Pat. No. 6,093,193, herein incorporated by reference.
One problem encountered with existing inserters is difficulty in loading the IOL into the inserter. The IOL is typically manually moved from a sterile environment to an inserter or associated cartridge using forceps or tweezers. Manual transfer of the IOL presents difficulties in maintaining both sterility of the IOL and the collect orientation of the IOL within the cartridge or inserter. Improper orientation of the IOL can result in inadequate surgeon control and even damage to the IOL during delivery into the eye.
These problems may be mitigated by preloading the IOL at the manufacturer into a cartridge or container that is designed to attach directly to the inserter during transfer of the IOL. The cartridge or container may be attached to the inserter either at the manufacturer or by the user just prior to surgery. In either case, the IOL is generally not stored directly in the inserter, since it is desirable to maintain the IOL in an unstressed state during storage in order to prevent deformation of the optic element. Thus, some type of transfer process is still generally necessary for loading the IOL into the inserter.
Prior to transferring the IOL into the inserter, the IOL stored in an unstressed state inside some type of storage case. During loading, the storage case is typically attached above or to one side of a load chamber that is in line with a pushrod used during insertion of the IOL into an eye. As the IOL is loaded into the load chamber, various means and mechanisms known in the art may be used to manipulate the IOL from an unstressed storage state to a state more suitable for delivery of the IOL into the eye of a subject or patient. In transferring the IOL from the holding chamber, the IOL is thus moved along an axis that is normal to the longitudinal axis of travel of the inserter pushrod. Such designs require relatively complex mechanisms to move IOL along two substantially orthogonal axes (i.e., the transfer axis and the longitudinal axis of the inserter pushrod). Another potential problem with such loading configurations is that the mechanisms for transferring the IOL may fail to provide adequate visibility of the IOL within the inserter. Inadequate visibility of the IOL makes it more difficult to provide adequate lubrication and ensure proper orientation and of the IOL.
It would be advantageous to provide devices, systems, and methods to better facilitate the transfer of IOLs into an inserter and/or placement of IOLs into the eye of a subject during an ocular surgery.